Conventional UVB has little or no observed increased risk of skin cancers. Recently, European researchers introduced UVB phototherapy with a narrowband wavelength at 312nm (TL-01) as a superior form of treatment for psoriasis as compared to conventional broadband UVB. Narrowband UVB produces faster clinical clearing of psoriasis and has been documented to have remission rates that are comparable to PUVA. We have completed analysis of twenty-two patients who have been treated with narrowband and broadband UVB on each vertical half of their body (1). As with the European studies, clinical resolution of psoriasis occurred faster on the narrowband UVB side with an 86% clearing rate as compared to 73% with broadband UVB. Some patients did not clear completely on the broadband UVB side but did clear totally when switched to whole body narrowband UVB. In addition, we demonstrated that NB-UVB is effective in the difficult-to-treat psoriatic patients: those with darkly-pigmented skin and very thick plaques. This experience indicates that whole body NB-UVB treatment needs to be individualized which could not have been predicted from half body exposures. Therefore, we want to establish guidelines for optimal dosing for NB-UVB, particularly in regard to the different skin types. There is a medical need to compile more data on the safety, efficacy, and dosing regimen when administering full body NB-UVB. Our plan is to enroll up to 20 patients in each of three skin type groups for treatment with whole body NB-UVB. Groups will be comprised of equal numbers of patients with skin type I-IV, V, and VI. As outlined in our previous phototherapy protocols, we will obtain skin biopsies before, during, and after treatment to follow pathological disease features.